/*
 * Copyright 2016 The Cartographer Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "cartographer/common/time.h"
#include <time.h>
#include <cerrno>
#include <cstring>
#include <string>
#include "glog/logging.h"

namespace cartographer
{
    namespace common
    {
        Duration FromSeconds(const double seconds)
        {
            return std::chrono::duration_cast<Duration>(std::chrono::duration<double>(seconds));
        }

        double ToSeconds(const Duration duration)
        {
            return std::chrono::duration_cast<std::chrono::duration<double>>(duration).count();
        }

        double ToSeconds(const int64 ticks)
        {
            return ToSeconds(Duration(ticks));
        }

        double ToSeconds(const Time time)
        {
            return ToSeconds(time.time_since_epoch().count());
        }

        double ToSeconds(const std::chrono::steady_clock::duration duration)
        {
            return std::chrono::duration_cast<std::chrono::duration<double>>(duration).count();
        }

        Time FromUniversal(const int64 ticks)
        {
            return Time(Duration(ticks));
        }

        int64 ToUniversal(const Time time)
        {
            return time.time_since_epoch().count();
        }

        std::ostream &operator<<(std::ostream &os, const Time time)
        {
            os << std::to_string(ToUniversal(time));
            return os;
        }

        common::Duration FromMilliseconds(const int64 milliseconds)
        {
            return std::chrono::duration_cast<Duration>(std::chrono::milliseconds(milliseconds));
        }

        double GetThreadCpuTimeSeconds()
        {
#ifndef WIN32
            struct timespec thread_cpu_time;
            CHECK(clock_gettime(CLOCK_THREAD_CPUTIME_ID, &thread_cpu_time) == 0) << std::strerror(errno);
            return thread_cpu_time.tv_sec + 1e-9 * thread_cpu_time.tv_nsec;
#else
            return 0.;
#endif
        }

    } // namespace common
} // namespace cartographer
